Juan and Sylvester Are Collaborating on a Project at Work,but

Juan and Sylvester are collaborating on a project at work,but are having trouble agreeing on objectives and goals.Henry senses the trouble they are having and steps in to help them refine their goals and come to an agreement.The manager is pleased with Henry's success in diffusing a potentially problematic situation and promotes Henry to project leader.Henry assumed which of Simmel's roles?

A) mediator
B) team leader
C) divide et impera
D) tertius gaudens